Posterior cerebral artery

Last revised by Assoc Prof Craig Hacking on 08 Nov 2021

The posterior cerebral arteries (PCA) are the terminal branches of the basilar artery and supply the occipital lobes and posteromedial temporal lobes.

The PCA is divided into four segments:

  • P1: pre-communicating segment
  • P2: post-communicating segment
    • from the PCOM around the midbrain
      • P2A (anterior): sub-segment courses through the crural cistern
      • P2P (posterior or ambient): sub-segment courses through the ambient cistern
    • terminates as it enters the quadrigeminal cistern
  • P3: quadrigeminal segment
  • P4: cortical segment
    • ​within the sulci of the occipital lobe
    • e.g. calcarine artery, within the calcarine fissure

The posterior cerebral artery curls around the cerebral peduncle and passes above the tentorium to supply the posteromedial surface of the temporal lobe and the occipital lobe. The visual cortex responsible for the contralateral field of vision lies in its territory. The macular part of the visual cortex often receives a dual blood supply from the PCA and the MCA, which explains the "macular sparing" phenomenon in some patients following a PCA infarct.

  • fetal origin of PCA: unilateral incidence 10%, bilateral incidence 8%
  • PCA fenestration: rare
  • duplicated PCA: rare, fetal origin and normal origin on same side (see case 1) 6

ADVERTISEMENT: Supporters see fewer/no ads

Cases and figures

  • Figure 1: PCA territory in blue
    Drag here to reorder.
  • Figure 2: PCA territory in blue
    Drag here to reorder.
  • Figure 3: Cerebral vascular territories
    Drag here to reorder.
  • Figure 4: normal COW anatomy
    Drag here to reorder.
  • Figure 5: brainstem arterial territories
    Drag here to reorder.
  • Case 1: accessory PCA arising from the terminal ICA
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.